Building Evolution – A Look at Materials, Part 1: Risk‎

Over the past several decades, the materials used to construct and build commercial and multi-unit residential structures have changed significantly. In particular, the construction and interior furnishings industries increasingly use plastics instead of natural materials such as wood, metal, glass and natural fibers. A recent review from the Healthy Buildings Network notes that “…Petrochemical, fossil fuel, and plastics industries are now pushing to increase their market growth in more durable goods, like building materials. The building and construction industry is already the second largest consumer of plastics after packaging.”

Over the past several decades, the plastics industry has benefitted from increasingly cheap chemical ingredients, huge investments in manufacturing capacity, and a wide variety of material choices. The result? A glut of lower-cost plastic products that have virtually taken over significant categories of building applications.

However, the apparent economic advantages of plastic materials hide their true cost. Analysis from the Center for International Environmental Law notes that continuing use of plastic in buildings will amplify negative effects of plastic production, use and pollution on human health and the environment: “There is compelling evidence that the rush to build new plastics infrastructure poses massive risks for communities, ecosystems, and the planet.”

Significant areas of concern include the following.

  • Toxins in Plastic: Exposure to carcinogenic and endocrine-suppressing chemicals leached into drinking water and emitted into interior air by PVC, PE, and other common plastics. Research by Purdue’s Andrew Whelton and others indicate significant levels of toluene, ethyl-tert-butyl ether, and unidentified contaminants passing from PEX pipes into drinking water for months and even years after installation.
  • Plastic Pollution: Degradation and pollution of food supplies, water sources, air quality and plant and animal ecosystems from petrochemical production and disaster-scale spills of plastic nurdles, from the well-documented tidal wave of discarded plastics and pervasive presence of microplastics in water, air and soil.
  • Resilience Issues: Inadequate performance and failure of building systems as less resilient plastic materials degrade and weaken over time due to damage from UV exposure and damage from heat.
  • Fire Risks: Alarming increases in fire risks to occupants and first responders from burning plastics, including emission of toxic smoke, firestopping failures, higher burn temperatures, and much faster times to flashover. Side by side burn testing of interiors by UL illustrates some of the fire dangers posed by higher levels of plastic materials.
  • Benzene Contamination of Drinking Water: After fires, contamination from damaged plastic pipes and components has been shown to spread through water infrastructure and make drinking water unsafe to use. Carcinogens such as benzene from melted and burned plastic prove hard to flush from systems, extending the tragedies of California wildfires by rendering whole communities unlivable long after flames have been put out.

These and other issues should prompt building professionals to consider more than initial costs when selecting materials. This follow up gives a summary of alternatives for common applications.